Marietta Flores Díaz


  • Senior Professor, Faculty of Microbiology, University of Costa Rica.
  • Ph.D. Karolinska Institute, Stockholm, Sweden, 2001
  • Lic. Microbiology and Clinical Chemistry, University of Costa Rica, 1995

Dr. Marietta Flores graduated from the University of Costa Rica with a Licentiate Degree in Microbiology and Clinical Chemistry. Her postgraduate studies were carried out at the Microbiology and Tumor Biology Center of the Karolinska Institute in Tumor and Cell Biology. Since 1999 she works as a researcher for the Clodomiro Picado Institute, she is also a teacher of the Faculty of Microbiology and the Postgraduate Study System of the University of Costa Rica. Dr. Flores was granted the Clodomiro Picado Twight National Award in Science on 2003 for her work “Role of Clostridium perfringens Phospholipase C in the Pathogenesis of Gas Gangrene” which contributed to the understanding of the mechanisms of action of this important bacterial toxin. The relevance of Dr. Flores’ contributions is evidenced in over 35 publications in prestigious international scientific journals, as well as by her participation in scientific congresses of high standing in different countries. 

Dr. Flores’ research has two main lines of focus: DNA cloning and expression coding through snake venom toxins, and the study of toxins produced by Clostridium perfringens using cell cultures, animal models, microscopy and molecular biology.

Publicaciones representativas de sus intereses de investigación

  • Flores-Diaz, M., Alape-Girón, A., Clark, G., Ichikawa, S., Hirabayashi, Y., Gutiérrez, J. M., Titball, R., & Thelestam, M. (2005). Cellular deficiency of gangliosides induces hypersensitivity to the cytotoxic effect of Clostridium perfringens  phospholipase C. The Journal of Biological Chemistry, 280, 26680-26689. doi:10.1074/jbc.M500278200
  • Arce-Estrada, V., Azofeifa-Cordero, G., Alape-Girón, A., Flores-Díaz, M. (2008). Immunization with a plasmid encoding a P-II metalloproteinase from Bothrops asper induces equine antibodies which neutralize the hemorrhagic activity of B. asper and C. durissus venoms. Vaccine, 27, 460-466.
  • Azofeifa-Cordero, G., Arce-Estrada, V., Flores-Díaz, M., Alape-Girón, A. (2008). Immunization with cDNA of a novel P-III type metalloproteinase from the rattlesnake Crotalus durissus durissus elicits antibodies which neutralize 69% of the hemorrhage induced by the whole venom. Toxicon, 52(2), 302–308. doi: 10.1016/j.toxicon.2008.05.023
  • Urbina, P., Flores-Díaz, M., Alape-Girón, A., Alonso, A., Goñi, F. M. (2011). Effects of bilayer composition and physical properties on the phospholipase C and sphingomyelinase activities of Clostridium perfringens α-toxin. Biochim Biophys Acta, 1808(1), 279-86. doi: 10.1016/j.bbamem.2010.08.011
  • Monturiol-Gross, L., Flores-Díaz, M., Araya-Castillo, C., Pineda-Padilla, M. J., Clark, G. C., Titball, R. W., Alape-Girón, A. (2012). Reactive Oxygen Species and the MEK/ERK Pathway are involved in the toxicity of Clostridium perfringens α-toxin, a prototype bacterial phospholipase C. J Infect Dis, 206(8), 1218-26.
  • Monturiol-Gross, L., Flores-Díaz, M., Campos-Rodríguez, D., Mora, R., Rodríguez-Vega, M., Marks, D. L., Alape-Girón, A. ( 2014). Internalization of Clostridium perfringens α-toxin leads to ERK activation and is involved on its cytotoxic effect. Cell Microbiol. 16(4), 535-47. doi: 10.1111/cmi.12237
  • Flores-Díaz, M., Monturiol-Gross, L., Naylor, C., Alape-Girón, A., Flieger, A. (2016). Bacterial Sphingomyelinases and Phospholipases as Virulence Factors. Microbiol Mol Biol Rev, 80(3), 597-628. doi:10.1128/MMBR.00082-15